Look what the YBAs have done to our art

12:00AM GMT 09 Dec 1998

EVERYONE knows that during the decade now coming to an end British art has been dominated by conceptual artists such as Damien Hirst and Rachel Whiteread. Less often noted is that another, very different, trend began to emerge as early as the mid-Nineties, when a single work by Dinos and Jake Chapman was first exhibited at the Venice Biennale.

It consisted of a three dimensional tableau made up of male manikins, shown castrated, decapitated and bound to a plastic tree trunk. Anyone could see that it was based on a famous print from Goya's Disasters of War. What made it so original was that like a video nasty or a pornographic film, there was nothing else to say about it. Having no particular meaning, it felt both mindless and mute - dumb in both senses of the word.

To appreciate just how different this was from the art we had been accustomed to seeing, you have to remember how all-pervasive the influence of Marcel Duchamp has been on British artists of the Eighties and Nineties. Like wit or intelligence, Duchamp's imprint on a work of art was not something you could see, but you could detect it in artists as different as Hirst, Whiteread, Tony Cragg, Richard Wentworth, and Mark Wallinger. All of them asked the viewer to bring the imagination to bear on art that used simple means and materials to make art that could deal with subjects ranging from nationalism and the environment to dreams, love, and the fear of death. Though the comparison is imperfect, you could liken the way they worked to the way poets make ordinary words resonate, either by juxtaposing them with other words, or by using allusion and metaphor.

Until the Chapmans came along, I'd have said that what Duchamp did could not have been undone. But now, suddenly, a new kind of art was being made in Britain, an art concerned not with content but with surface. When, earlier this year, Charles Saatchi held a major exhibition of the paintings of the bland American pop artist Alex Katz he found a kind of anti-Duchamp to provide an art-historical precedent for figurative art that has no subtext, no meaning, no critical distance from what it depicts.

Die Young Stay Pretty (at the ICA until January 10) and Dumbpop (at the Jerwood Space until January 17) are both important shows. Whether or not you like what is happening in them, they signal the most radical new development in British art in a decade.

The look of both shows is different from the cool, monochromatic exhibitions we've become used to in the Nineties. Both are full of big colourful paintings and sculptures and there's even a certain amount of craft. But there is none of the Chapmans' gore or porn, no installation, not much video, and nothing at all that makes any demands on the brain. Indeed, both galleries look a bit like playpens. The exuberance, energy and campy aesthetic of these young artists reminded me of the American Pop artists of the Sixties. It's only when you spend a little time with their art that you realise how little of the optimism that was so integral to art of Warhol, Oldenburg, Lichtenstein, Dine and Rosenquist comes into their outlook on life.

At both exhibitions you can see the work of Jun Hasegawa, who makes giant cut-out cartoon images showing vacuous, pretty teenage girls and boys who look to me like characters from the television sitcom Happy Days. Cheerful as models in toothpaste commercials, their smiling faces betray not the slightest hint of sexuality, tension, or emotion. These are the offspring of Katz's well-heeled suburbanites. Like their parents, they literally have no depth, no shadows, no moral or spiritual substance. Though I've never taken Prozac, this is what I imagine it must be like. You don't feel good or bad, you feel nothing, and yet you think you're as happy as a lark.

If Hasegewa's teenagers have thoughts at all, they are of the sort that can be contained in a cartoonist's thought bubble.

Philippe Parreno has provided a silvery flotilla of these in the form of helium-filled balloons floating on the ceiling of the Jerwood Space. Whatever is said in such a bubble has to be short, sweet, and simple. The effect of Parreno's work must have been terrific at the opening-night party, with dozens of real people standing underneath the silver bubbles, mouthing the congratulatory platitudes that pass for conversation on these occasions. Part of the joke, of course, is that the artwork is itself a one-liner. You see it, you smile, you forget it.

Martin Maloney offers a single mural-sized canvas at the ICA, Hey Good Looking (after Poussin's The Choice of Hercules), a cartoon updating of the myth enacted by a muscleman choosing between Vice (a dark-haired hooker) and Virtue (a blonde in a dress). With its inane high spirits, Maloney's art reminds me of the Royal Academician Ken Kiff, a likeable artist with the same whimsical sense of humour, the same love of colour, and the same faux-naive way of painting. With its confident scale, painterly surface, and pretty colours, Maloney's art has the commerical appeal we last saw in some of the painters who came to prominence in the Eighties. But look what happened to them: art without emotional or moral substance doesn't sustain its appeal for long.

But then, that could be said of all these artists. Gary Webb's I Love Black Music looks like an over-sized executive toy, a roly-poly kinetic figure with a manikin's head which stands on the gallery floor shaking, rattling, and rolling in an eternal, mindless dance.

In Kate Bright's romantic seascapes, dark waters glisten with moonlight made by gluing silver glitter over swirls of black acrylic paint. Hers are the sort of works that are usually sold on Sundays along the Bayswater Road, except that they are clever enough to flaunt their own soppiness.

Disarmed by their greeting-card appeal, you get off your high horse, lighten up, and admit that they aren't so bad. And once you do, you've become an accomplice in this whole process of dragging art down to its lowest common denominator. But what can you say against this work? Resist? Don't look? Leave the gallery in a huff? It is, after all, only a painting.

When an artist paints a dumb picture knowingly, already it's not so dumb. Peter Davies - by far the most sophisticated artist in either show - makes cack-handed parodies of avant-garde art, except that where the originals were difficult and austere, his paintings are big, bright, and fun to look at. In Joseph Beuys (Text Painting) he has a go at critics, art historians and, above all, artists like Beuys who exhibit texts as works of art.

In a performance of inspired lunacy, he paints a surprisingly accurate diagram in which he summarises pretty much the whole of contemporary-art practice - where it comes from and where it is going. Entertaining as all this is, it is hard to build a career on bird-brained humour, no matter how good natured or how cleverly packaged. I wish all these artists well, but I suspect most will disappear without a trace.